The present invention relates to adducts of hydrocarbyl substituted phenols, carbonyl compounds, and carboxy-substituted carbonyl compounds, and dispersants prepared therefrom, useful as lubricant additives.
Condensation products of hydrocarbyl phenols and carboxy-substituted aldehydes, such as glyoxylic acid, are known. For example, U.S. Pat. No. 5,281,346, Adams, Jan. 25, 1994, discloses a two-cycle engine lubricant comprising alkali or alkaline earth metal salts of carboxylic aromatic acids having a formula ##STR1## wherein T is selected from the group consisting of ##STR2##
U.S. Pat. No. 5,356,546, Blystone et al, Oct. 18, 1994, discloses metal salts similar to those of U.S. Pat. No. 5,281,346. The salts find utility in lubricants and fuels other than 2-cycle engine lubricants and fuels.
Condensation products of phenols and formaldehyde are also known. For example, U.S. Pat. No. 3,793,201, Karn, Feb. 19, 1974, discloses polyvalent metal salts of bridged phenols, which are alkylated phenol-formaldehyde condensation products.
U.S. Pat. No. 5,039,437, Martella et al., Aug. 13, 1991, discloses alkylphenol-formaldehyde condensates as lubricating oil additives. The alkyl groups are essentially linear, have between 6 and 50 carbon atoms, and have an average number of carbon atoms between about 12 and 26. Blends of these additives with middle distillates and lubricating oil compositions, whose low temperature flow properties are significantly improved thereby are disclosed.